Effect of C, Al and Si additions on the magnetic properties of melt-spun NdFeB alloys

✍ Scribed by Pankyu Choi; Hiromitsu Ino

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 624 KB
• Volume: 181-182
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(94)90789-7

✦ Synopsis

We have studied the effect of the addition of C, AI or Si on the magnetic properties of Nd-Fe-B-based alloys crystallized from amorphous states. The amorphous Fe77.sNd15(B1 _xMx)7.5 (M-= C, A1 or Si and x = 0-1) alloys were prepared using the melt-spinning method. An increase in C content increases the remanence B r of Fe77.sNdls(Bl_xCx)7.5 alloys crystallized at 873 K, and the maximum energy product (BH)max is obtained as 93 kJ m -3 in the composition range x = 0.15-0.25. On addition of A1, the coercivity iHc is at a maximum ( 1.55 MA m-~) at x = 0.25. It is concluded from the variation of the relative intensities of the Mfssbauer spectra that AI or Si atoms are preferentially substituted for one or two (k 2 and probably ]'2) Fe sites in the Nd2Fel 4 B phase. M6ssbauer spectra show that C atoms occupy the same site as B atoms in the Nd2Fe14B phase and give a similar effect to that of B. The average magnetic hyperfine field of Nd2Fe14C is about 93% of that of Nd2Fe~4 B.